Trench-jack.



J. C. FRENCH.

TRENCH JACK. APPLICATION FILED JAN. 11. 1918.

Patented Oct. 15, 1918.

JAMES C. FRENCH, OF

CHICAGO, ILLINOIS, ASSIGNOR TO FREDERICK C. AUSTIN, OF

CHICAGO, ILLINOIS.

TRENCH-JACK.

. Application filed January 11, 1918.

- resident of Chicago, county of Cook, and

State of Illinois, have invented a certain new and useful Improvement in Trench- Jacks,'of which the following is a specification.

This invention contemplates a novel form of trenchjack for use in transverselyv bracing. the side walls of a trench, thereby to prevent the walls from caving in, and whereby the workmen may lay the tile or perform the other necessary operations at the bottom of the trench. For example, in the use of a trenching machine or excavator, such as those commonly employed for making trenches for the laying of tile, or for any other purpose,it frequently becomes neces sary to employ boards or planks along the sides of the trench, to keep the banks from caving in, and this is especially true when the machine is working in sandy soil. The improved jack contemplated by this invention is adapted to be easily inserted between the side walls of the trench, and adjusted to hold the boards or planks in position, and may be easily removed when no longer required for this purpose.

Generally stated, therefore, the object of the invention is to provide a novel and imvproved form of trench jack which can be easily and quickly inserted and operated to brace the side walls of the trench, and which can be adjusted to suit the width of the trench, as well as readily removed when no longer needed. I

A special object is to provide a trench jack of this general character in which the mechanism for the operation thereof is actuated by a member upon which downward pressure may be exerted, as by placing the foot thereon, so that the mechanism will be operated and forced into position to retain the opposite ends or shoes of the jack tightly .in position against the side walls of the "trench.

It is also an object to provide certain de- -.tails and features of construction and combi- Specification of Letters Patent.

cross-section; the operative position of the trench jack being shown in full lines, and its inoperative position in dotted lines.

Fig. 2 is an enlarged detail section on line 22 in Fig. 1.

As thus illustrated, the invention comprises a shoe 1 connected by a transverse pivot bolt 2 with one horizontally disposed arm 3, and another shoe 4 connected by a transverse pivot bolt 5 with another horizontally disposed arm 6, the latter being supported by a transverse pivot bolt 7 on the slide 8, so that the pivot bolt 7 forms a toggle-joint. The slide 8 is adjustably held in place on the arm 3 by the transverse bolt 9, which latter is adapted to be inserted through any one of the holes 10 provided in said arm for this purpose. Also, as will be seen, the arm 6 is provided with a plurality of bolt-holes 11 for the bolt 7 whereby the latter can be adjusted to different positions on this arm. The arm 6 is extended to form a lever and has its end provided with a fiat member 12 which forms a footpiece, and which serves also as a stop to engage the top of the arm 3 when the togglejoint is forced downward.

The method of using the; trench jack is as follows :-The device is placed between the other useful ends, I

joint 7 is forced below the center, so to speak, or below the line rcw which represents the straight line of thrust passing through the pivotal points 2 and 5 of the shoes. The toot-piece 12 engages the top of the arm 3, to limit this movement of the toggle-joint below said line, so that the trench jack is thus retained in its operative position. However, pressure exerted upward at the botom ot' the toggle-joint, if suliicient, will force the oint above said line :v-m, and then the trench jack will collapse, as shown in dotted lines in Fig. l, and may be lifted out of the trench. For trenches of different widths, the bolts 7 and 9 are adjusted to different holes 10 and 11 in the two toggle-arms 3 and 6, so that the jack may be adjusted in length to suit the requirements.

Thus it will be seen that a very powerful device is provided for use as a transverse brace betwen the side walls of the trench. It can be operated by downward pressure of the foot, or by resting a heavy object thereon, and is easily adjusted in position and removed from the trench. The device is not liable to get out of order, as it will operate even when badly rusted. Also, it can be manufactured at comparatively small expense.

The arms 3 and 6 can be of any suitable character, but as amatter of further and special improvement, they are preferably constructed as follows :The arm 3 is a section of pipe, and the arm 6 is of fiat strap metal bent around so that this arm is, in efie'ct, composed of two parallel portions connected at their outer ends by the footpiece or member 12, so that the upturned and united end portions of the arm 6 embrace the sad section or" pipe. The slide 8, with this construction, is preferably in the form of a casting, as shown, having two depending ears for the bolt 7 by which the bifurcated arm 6 is pivoted thereon. This, it will be seen, insures a very strong construction.

Of course, when the bolt 9 is inserted in place, in the manner shown, it serves as means to keep the axis 7 of the toggle mechanism parallel with the axes 2 and 5 of the shoes 1 and a, inasmuch as the slide 8 cannot rotate on the pipe 3 when the bolt is thus inserted.

What I claim as my invention is 1. A trench jack comprising shoes to engage the opposite side walls of the trench, a toggle connection between said shoes to force them away from each other, said toggle connection comprising an arm pivoted on each shoe, a slide on one arm, means to hold said slide in adjusted position on the one arm, according to the width of the trench, means to pivot the other arm between its ends on said slide, so that the arm thus pivoted on said slide serves as a lever by which to operate said toggle, and a stop on the end of said pivoted arm to rest on said one arm when the toggle is forced downward.

2. A trench jack comprising shoes to engage the opposite side walls of the trench, and a toggle connection between said shoes to force them away from each other having means to keep the axis of the toggle parallel with the axes of said shoes, said toggle connection having a foot-piece to force the toggle downward and serving as means to limit this movement of the toggle joint below the line of thrust (m -50) between the pivots (2 and 5) of the shoes.

3. A trench jack comprising shoes to engage the opposite side walls of the trench, a toggle connection between said shoes to force them away from each other, said toggle connection comprising an upper arm pivoted on one shoe, a lower arm pivoted on the other shoe, a slide on the upper arm, means to hold the slide in. adjusted position on the upper arm, means to pivot the lower end of the slide in difierent positions on said lower arm, and a foot-piece on the arm adjustably pivoted on the slide, the two arms being substantially parallel when said foot-piece is resting on top of said upper arm.

i. A. trench jack comprising a pair of shoes to engage the opposite side walls of the trench, mechanism to :torce the shoes apart, operatively connected thereto having means to keep the axesot said sh'oesparallel, and a member to receive downward pressure thereon and connected to operate said mechanism.

5. A trench jack comprising a pair "of shoes to engage the opposite side walls "of the trench, mechanismto force the shoes apart, operatively connected thereto having means to keep the axes of said shoes parallel, a member to receive downward pressure thereon and connected to operate said mechanism, said mechanism including a pivoted lever, and said member being a foot-piece on an upturned portion forming a guide on the free end of said lever.

6. A trench jack comprising a pair of shoes to engage theopposite side walls of the trench, and mechanism to force the shoes apart, operatively connected thereto, including a member to receive downward pressure thereon, connected to operate said mechanism, and two parallel portions which are pivot'edto form an arm which swings up and down, with said member forming a rigid connection between said portions at the free endot' said arm.

7. A trench j aclr comprising shoes to engage the opposite side walls of the trench, a toggle connection between said shoes to force them away from each other, said togward, said one arm consisting of a section gle connection comprising an arm pivoted of pipe, and said other arm being composed 10 on each shoe, a slide on one arm, means to of two parallel sections rigidly connected tohold said slide in adjusted position on the gether at one end by said stop.

arm, according to the width of the trench, Signed by me at Chicago, Cook county, means to pivot the other arm on said slide, Illinois, this second day of January, 1918.

and a stop on said other arm to rest on said one arm when the toggle is forced down- JAMES C. FRENCH.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. O. 

